Put each verb into the past simple or past continuous. 1.

1. I was having a shower when suddenly there was a knock at the door. 2. It started raining while I was walking home and I got completely wet. 3. "Where were you and what were you doing at ten last night?" asked the detective. 4. I did not hear him when he told me what his name was. 5. Kelly was working when I called her so we did not talk for long.

Past Indefinite is formed with the help of the suffix - ed for regular verbs. We use the second form of verbs for irregular verbs. 

Past Continuous is formed was + verb + ing.